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Topic Review (Newest First)

01-31-2013 09:34 PM

amc49

'your fans should come on if your AC comes on'

I have recently discovered that is not necessarily true. If cold during winter the fans OFTEN do not come on with a/c , it will work by itself. The PCM regulating something there. After putting LEDs on low and high fan and a/c compressor itself I found that out, same on both my focus cars. Now, during summer, fans do pretty much come on with the a/c.

01-31-2013 04:51 AM

whynotthinkwhynot

If you're hitting your gas and the temp changes, then yes you have some sort of issue with the temp sensor. However, your fans should come on if your AC comes on. Now the question is- does the AC work? If the AC doesn't work- like from low pressure- then the circuit isn't complete, and the fans aren't turned on.

Fix your valve cover gasket and replace your temp sender- see what happens. It doesn't seem like you're figuring anything out from all this testing and questioning.

If you still want to test stuff, then if I were you I'd do a continuity test on the negative to make sure it's connected somewhere. You should show .1 ohms if it doesn't read 0.0 ohms. You can also test the fan diodes which are in the fuse box. That's the backwards arrow symbol on your schematic. You should get continuity with one polarity, and open circuit with the other polarity. I would think that the ground connection was lost before you lost both diodes.

01-31-2013 03:53 AM

amc49

Uh, if you can read the electric schematic then you don't need to ask how many fans come on, it is evident.

01-30-2013 10:21 PM

Focuslu86

Quote:

Originally Posted by amc49

Turning on the motor and then a/c or defrost on may not work to test fans in very cold weather. Even though fans switch on with a/c, they often don't in the cold based on PCM control.

i do live in miami, and its not cold at all! i just got the ford focus 2001 diagram and am tracing all the components, relays, and connectors to the cooling system! when the engine gets hot, it turns on one fan or both to keep it under 225 F? or just one fan turns on? I am checking the diagram for engine cooling system for a zetec-e without air conditioning, meaning thats the one that cools down the engine, correct?

01-30-2013 08:51 PM

amc49

Turning on the motor and then a/c or defrost on may not work to test fans in very cold weather. Even though fans switch on with a/c, they often don't in the cold based on PCM control.

01-30-2013 06:21 PM

Focuslu86

Quote:

Originally Posted by Magus2727

Then just replace the head temp sender and while your at it replace the valve cover gasket. its $15....

But if your temp is getting up to the red and your fans are not working then you have something going on. So you have verified that the relay does work and have by passed the relay?

No I do not have either of the scanners you have asked about.

Have you tested conductivity? Test from Battery to Relay, relay to fans, relay to control module. If you have the wire diagram then at what point if you apply 12V do the fans no longer turn on? When you hit the gas and your temp goes down do the fans turn on? Perhaps a stuck thermostat is also in your problem? would not be the first time a new thermostat was stuck. did you get Ford OEM or buy some aftermarket part from a chain store?

I replaced the thermostat recently and used and aftermarket part from advanced autoparts...did some research with that water pump and it seemed to be of good quality! I took it to an car electrician, like a week ago...he told me that the fans were working...that he tested the relays, fuses, everything! and supposedly was fine. I checked the temperature level of my car with a scan tool (the fans were supposed to kick in at 225 farenheits), but the fans didnt go on! i even turn the A/C on, and the fans dont work at all...this cooling system garbage is driving me nuts...btw, I have change water pump, thermostat housing and thermostat, radiator top hose since they were leaking coolant....

01-30-2013 05:18 PM

Magus2727

Then just replace the head temp sender and while your at it replace the valve cover gasket. its $15....

But if your temp is getting up to the red and your fans are not working then you have something going on. So you have verified that the relay does work and have by passed the relay?

No I do not have either of the scanners you have asked about.

Have you tested conductivity? Test from Battery to Relay, relay to fans, relay to control module. If you have the wire diagram then at what point if you apply 12V do the fans no longer turn on? When you hit the gas and your temp goes down do the fans turn on? Perhaps a stuck thermostat is also in your problem? would not be the first time a new thermostat was stuck. did you get Ford OEM or buy some aftermarket part from a chain store?

01-30-2013 02:29 PM

Focuslu86

my car only overheats when I am stuck in traffic...the car starts acting weird, but as soon as i hit the gas...the gauge goes down to normal. I have turned on my A/C to see if the fans would work, but nothing at all (i put he knob to 3 with cold all the way, turned on A/C switch, recirculation switch)...and my fans wont move! i have used a master probe 3 to test the fan motor and both work (its like using jumper wires from the batt to the fan motor). It is a very annoying issue since the car would show that it over heats...i have replaced hoses, water pump, thermostat housing (with thermostat) since the heat to the parts would damage them completely...

01-30-2013 09:48 AM

Magus2727

Are you overheating? Perhaps its just could enough outside that your fans rarely turn on? If you turn the AC on does the aux (2nd) fan turn on?

01-30-2013 07:27 AM

Focuslu86

thanks for all the messages!
I have tested my resistor and motor fans and they work perfect! my cluster gauge works, but sometimes it takes a couple of mins to work....can a bad head temperature sensor affect the functionality of the fans? like making them not to come out? i mean i have the wiring and diagram from ford, and I checked all the component: engine cooling fan relay, high speed engine cooling fan relay, fan resistor, motor 1&2. There are 2 more left: dual pressure switch and cylinder-head temperature pressure...idk if these 2 control the fans directly? or if they can make the fans to work or not

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